Full-arch restoration with the NEXUS IOS® system: A retrospective clinical evaluation of 37 restorations after a one year of follow-up.

OBJECTIVES: Report the results with a novel workflow of digital restoration for completely edentulous patients with implant supported full arch fixed dental prostheses (ISFDP). METHODS: This multicenter retrospective clinical study was based on the evaluation from a cohort of 29 patients restored with 37 ISFDP designed and manufactured from the data captured by a direct intraoral scan, using a novel full digital system (NEXUS IOS®, Osteon Medical, a Keystone Dental Group company, Melbourne, Australia). Data was collected over a 3-year period, in six different dental centers. This study reported on the clinical parameters including: precision of marginal fit, functional and aesthetic integration of Nexus ISFDP. All patients were followed for a period of one year post delivery. Implant survival, biologic and prosthetic complications were assessed, at one year. A statistical analysis was conducted. RESULTS: All 37 ISFDP were deemed clinically acceptable on insertion. Implant survival at one year was 100 %. The biologic and prosthetic complications were minimal during the follow-up period. CONCLUSIONS: ISFDP, designed and manufactured using the NEXUS IOS® system, are clinically acceptable, with a low incidence of complications at one year. Long-term clinical studies are needed. STATEMENT OF CLINICAL RELEVANCE: Within the limitations of this study (retrospective design, small patient sample, limited follow-up) the NEXUS IOS® system seems to represent a viable solution for the restoration of completely edentulous patients with ISFDP, in a full digital workflow.

Complete Digital Workflow for Prosthesis Prototype Fabrication with Double Digital Scanning: Accuracy of Fit Assessment.

PURPOSE: To assess the accuracy of a complete digital workflow protocol for fabrication of printed prosthesis prototypes for maxillary immediate loading treatment. MATERIALS AND METHODS: A maxillary stone cast with 4 abutment-level implant analogs with adequate antero-posterior spread was fabricated. This stone cast served as a reference cast and a zirconia prosthesis was also fabricated to serve as an interim prosthesis. Double digital scanning was used for digital scans of the reference cast and the interim prosthesis, respectively. An intraoral scanner (TRIOS® 3) was used to capture the standard tessellation language (STL) files. These STL files were then imported to computer-aided design (CAD) software (Exocad DentalCAD) and superimposed into a final design STL file that was exported to 3 different (Form 3b+, Carbon M2, Sprintray Pro95) three-dimensional (3D) printers to produce a total of 90 printed prototypes (n = 30 from each 3D printer). Two blinded clinicians assessed the accuracy of fit of each digitally fabricated prosthesis prototype on the reference cast, utilizing the screw-resistance test and radiographs. The Fisher's exact test was used to test the difference between the groups. RESULTS: Out of the 90 digitally fabricated prototypes, 86 (95.6%) presented with accurate fit. The accuracy of fit ranged from 87% (26/30) for Sprintray Pro95 to 100% (30/30) for the Form 3b+ and M2 Carbon groups. CONCLUSIONS: Digitally fabricated prosthesis prototypes can be generated with a complete digital workflow leading to clinically acceptable fit, while reducing the number of appointments and treatment time. The 3D printer had an effect on the accuracy of prosthesis prototype fit.

Preprosthetic Surgery.

Preprosthetic oral and maxillofacial surgery has changed dramatically over the last 3 decades. Surgical preparation for dentures has been displaced by site development for implants. Nonetheless, there is still a role to play for several preprosthetic procedures. In this article, historical context is provided, enduring concepts are reviewed, and procedures that remain relevant are described and discussed.